Extensible clamp



Aug 3'f1954 c. c. LANG EXTENSIBLE CLAMP f Filed March 15, 1952 FIG?.

FIGS.

FIG. 4.

H IS ATTORNEY Patented Aug. 3, 1954 I, ff

/" EXTENSIBLE CLAMP Clarence C. Lang, Los Gatos, Calif.

3 Claims.

present invention relates to clamps, and ypertains more particularly to an extensible bar In woodworking, such as cabinet and pattern making, it frequently is necessary to glue a plurality of boards together. For such work it is customary practice to employ one or more clamps each having an elongated body portion, a xed or adjustable jaw on one end of the body portion, and a screw-actuated clamp member on the other end of the body portion.

The present invention contemplates the provision of an improved extensible bar clamp. The invention also provides for a bar clamp having a wide range of adjustment so that the number of styles of clamps required will be minimized. The invention also has for an object the provision of a clamp which can be shortened to occupy a small space for shipping or storing, but which can be elongated by a series of increments to span a work piece of substantial dimension.

These and other objects and advantages of the invention will Ibe apparent from the following description and the accompanying drawings, comprising one sheet, wherein:

Fig. 1 is a side elevational view of an extensible bar clamp embodying the present invention, intermediate a body portion, and an adjustable jaw member being broken away.

Fig. 2 is an edge elevational view of the clamp shown in Fig. 1.

Fig. 3 is a transverse sectional view taken along line 3 3 of Fig. 1.

Fig. 4 is a transverse sectional view taken along line 4 4 of Fig. 1.

Fig. 5 is a transverse sectional view taken along line 5 5 of Fig. 1.

Fig. 6 is a transverse sectional view taken along line 5 6 of Fig. 2.

Fig. '7 is a fragmentary longitudinal sectional view taken along line 1 1 of Fig. 1.

In the illustrated form of the invention, a bar clamp A, has an elongated body assembly B, an adjustable jaw member C, and a clamping screw D.

The elongated body assembly B comprises a rst or outer steel channel portion Ill with va stop plate II secured by screws I2, I2 across an end thereof. The ends of the stop plate II project beyond the sides of the channel member I0 to limit the outward movement of the adjustable jaw member C which is mounted for sldable adjustment on the channel member I0.

While the stop plate I I and several of the other parts of the present clamp A are shown as being Application March 15, 1952, Seria-l No. 276;'734

joined by screws, it is obvious that most if not all of these connections may be made by welding or silver soldering if desired.

The jaw C comprises a metal block I3 having a recess I4 therein to receive the channel member I0 freely therein. A plate I5 is secured to a side of the block I3 to extend across the recess I4 to retain the channel member I0 therein (Figs. l and 2). Sufficient clearance space I3a may be provided between the channel member I0 and the jaw member C to permit the jaw member to be moved slidably over la keeper band to be described later herein.

A jaw anchoring pin I1 is slidably mounted in a hole I8 provided therefor in the jaw block I3, the inner end of the pin I1 being of a size to enter any of a plurality of anchor holes I9 provided along one side flange of the channel member It. A coil spring 20, held in compression between an offset shoulder 2I in the 'hole I9 and a flange 22 'surrounding the pin I`1 urges the pin axially inwardly to move the inner end of the pin I1 into any of the holes I9 with `which it is brought into register. A knob 23, screwed onto the threaded outer end of the pin I1, provides a grip for manually retracting the pin, and also (Fig. l) acts as a stop to limit the inward movement of the pin I1 under the impulse of the spring 2e.

A U-bracket 24 is formed to t onto the ope posite end of the channel member I0 from the stop plate II to extend` across the channel therein, and is secured thereto by screws 25. A latch lever 21 is pivoted on a pin 28 extending transversely between `a pair of ears 29, 29 (Figs.

, 2, 6 and 7) mounted on the bracket 24.

A'latch pin 30 is mounted in one end of the latch lever 21 and extends inwardly so as to enter any of a plurality 0f holes 3I (Figs. 1 and 7) provided in an inner channel member 32 with which it is brought into register. A notch 33 in the bracket 24 is of a size to permit the latch pin to move freely upon pivotally moving the latch lever v21. A coil spring 34 is held in compression between the bracket 24 and the latch lever 2.1. Thespring 34 is retained against displacement by a pin 35 mounted on the bracket 24 and inserted in the inner end of the spring 34. A recess 31 in the lever 21 receives the outer end of the spring 34.

The second or inner channel member 32 is inserted 4for slidable movement in relatively reversed position in the first or outer channel member I0 so as to move slidably therein within the bracket 24. Sufcient clearance space 38 (Fig. 4) is provided between the outer sides and 3 edges of the inner channel member 32 and the outer channel member I to receive a bar keeper band to be described later herein.

A keeper band 39 is provided around the iirst or outer channel member I0 to have a sliding fit thereon, and is secured by screws 4i) to the left hand end (as illustrated in Figs. 1 and 2) of the inner channel member 32. This keeper band 39 retains within the first channel member l0 the left hand end of the inner channel member 32 in any slidably adjusted position of the inner channel member 32.

A U-shaped bracket 4l is mounted on the projecting or right hand end of the inner channel member 32 to extend across the open side of the channel therein, and is secured to the channel member 32 by screws 42. A latch lever 43, similar to the latch lever 21 is mounted on the bracket lil to engage any of a plurality of holes 44 (Figs. l and 2) provided in a rectangular bar member 45.

The bar member 45 is inserted for slidable adjustment in the inner channel member 32. The U-bracket 4l retains the outer or right hand portion of the bar member d5 within the inner channel member 32. A keeper band d? (Figs. l, 2 and 5) encircles the inner channel member 32 and is secured by screws i8 to the left hand end (as illustrated in Figs. 1 and 2) of the bar member 45. The keeper band 41 is of a thickness to nt slidably within the clearance space 38 provided between the outer and inner channel members l! and 32.

The projecting or right hand end portion es (Figs. 1 and 2) of the bar member 135 is bent to extend laterally from the remainder of the bar member 45, and a usual pressure or clamp screw 5B is threadedly mounted in a boss 5I on the outer end of the lateral projection 49.

The manner of using the invention will be apparent to anyone familiar with bar clamps. For example, the adjustable jaw C may be moved slidably along the outer channel member l0 upon withdrawing the anchor pin H clear of the outer channel member l0.

Sufficient clearance space l3a (Figs. 1 and 2) is provided between the walls of the recess iii and the outer channel member l0 if desired to allow the jaw member C to be moved slidably over the keeper 39. When so arranged, the keeper 35 f preferably should be of thin material in order to minimize the amount of clearance space i3d required. Since this keeper 3S is not subjected to severe stresses in using the device it is not necessary that it be very strong.

The inner channel member 32 may be extended or retracted as desired upon tilting the latch lever 2l to withdraw the latch pin 3B from any of the openings 3l in which it may be inserted. Upon releasing the latch lever '2 and relatively moving the inner channel member 32 to bring the latch pin 30 into register with one of the openings 3| in the side flange 32a, the spring 3s will tilt the lever 21 in a counter-clockwise direction to the position shown in Figs. 2 and 7 to again latch the two channel members lll and 32 together. The relatively extended 0r retracted position of the bar member 5 also can be adjusted in a similar manner by manipulating the latch lever 43.

While I have illustrated a preferred embodiment of my improved bar clamp it will be understood by those familiar with the art that various changes and modifications may be made in the details thereof without departing from the spirit and scope of the invention as set forth in the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is defined in the following claims.

I claim:

l. An extensible clamp comprising a first relatively wide and shallow channel member having a plurality of anchor elements disposed lengthwise thereof, a jaw member slidably mounted on said rst channel member to extend laterally therefrom, means on said jaw member for interiockingly engaging selected anchor elements on said rst channel member, a second channel member of a size and shape to fit closelywithin the first channel member mounted in reversed position within said first channel member for slidable movement lengthwise therein, means for securing the two channel members in relatively adjusted position, an inner member cfa size and shape to nt closely within the second channel member inserted in the second channel member for slidable movement lengthwise therein,.

means for securing the inner member in longitudinally adjusted position within said second channel member a laterally extending screw mounting element mounted on said inner member' longitudinally opposite said jaw, and a clamping screw threadedly engaging said screw mounting element to exert pressure on a work piece interposed bet veen said clamping screw and said jaw.

2. An extensible clamp comprising a relatively wide and shallow first channel member having a plurality of anchor elements disposed lengthwise thereof, a jaw member slidably mounted on said rst channel member to extend laterally therefrom, means on said jaw member for interlockingly engaging selected anchor elements on said first channel member, a second channel member of a size and shape to t closely within the first channel member mounted in reversed position within said first channel member for slidable movement lengthwise therein, a support mounted on said first channel member in position to retain the second channel member therein, a spring biased latch on said support for securing the two channel members in relatively adjusted position, a bar member slidably inserted in the second channel member for slidable movement lengthwise therein, a support on said second channel member in position to retain the bar member therein, a spring biased latch on said latter support for securing the bar member and second channel members in relatively adjusted sition, a laterally extending element mounted on said bar member longitudinally opposite said jaw, and screw means having operative connection with said laterally extending element to exert pressure on a work piece interposed between said laterally extending element and said jaw.

3. An extensible clamp comprising a first relatively wide and shallow channel member having a plurality of anchor elements disposed lengthwise thereof, a jaw member slidably mounted on said first channel member to extend laterally therefrom, means on said jaw member for interlockingly engaging selected anchor elements on said rst channel member, a second channel member of a size and shape to t closely within the first channel member mounted in reversed position within said first channel member for slidable movement lengthwise therein, a keeper band mounted slidably to encircle the nrst channel member and secured to the second channel member adjacent an end thereof, a support mounted on said rst channel member in position to retain the second channel member therein, a spring biased latch on said support for securing the two channel members in relatively adjusted position, abar member of a size and shape to fit closely Within the second channel member slidably inserted in thesec/ond channel member for slidable' movement'lengthwise therein, a keeper band mounted slidably to encircle the second channel4 member and secured to the bar member, a support on said'second channel member in position to retainthe bar member therein, a spring biased latch on said latter support for securing lthe bar member and second channel members' inrelatively adjusted position, a laterally extending element/on said bar member longitudinally opposite said jaw, and screw means hav- References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 52,958 Briggs Mar. 6, 1866 870,761 Benson Nov. 12, 1907 1,004,743 Cobb Oct. 3, 1911 1,241,215 Hoffman Sept. 25, 1917 1,447,519 Schade Mar. 6, 1923 1,543,197 Ulrich June 23, 1925 1,583,611 Seely May 4, 1926 1,930,177 Miller Oct. 10, 1933 2,610,875 Wheelden Sept. 16, 1952 

